Remove rig_flush from rigctlcom.c -- OmniRig not happy being flushed

https://github.com/Hamlib/Hamlib/issues/273

tests/rigctlcom.c

@@ -614,7 +614,6 @@ int main(int argc, char *argv[])
         char *stop_set = ";\n\r";
 
         memset(ts2000, 0, sizeof(ts2000));
-        rig_flush(&my_com);  // get rid of anything in the queue
 
         status = read_string(&my_com,
                              ts2000,